Minamata Convention on Mercury

Background

The Minamata Convention on Mercury is an international treaty to protect human health and the environment from the harmful effects of mercury. Australia ratified the Minamata Convention on 7 December 2021, supporting global efforts to reduce exposure to mercury and protect human health and the environment.

Mercury and its use in the workplace

Mercury and mercury compounds exist in metallic (elemental), inorganic and organic forms, which can differ in the effects on human health and the environment. In Victoria, mercury is used in the manufacturing and supply of amalgam fillings for the dental industry. Mercury may also be present in Victorian workplaces in interim storage or as mercury waste.

In addition, mercury containing products can include thermometers, barometers, fluorescent bulbs, batteries and electrical switches. Mercury waste may be found at:

• fluorescent light bulb recycling facilities
• medical waste facilities
• industrial and domestic waste facilities

Health effects of mercury exposure

Mercury is a substance that has the potential to harm human health and is classified as a hazardous substance in accordance with the Globally Harmonised System of Classification and Labelling of Chemicals (GHS).

Further information on the GHS classification for mercury is available from Safe Work Australia.

Metallic and organic mercury is toxic to the central and peripheral nervous systems. Inhalation of mercury vapour can produce harmful effects on the nervous, digestive and immune systems, lungs and kidneys and may be fatal. The inorganic salts of mercury are corrosive to the skin, eyes and gastrointestinal tract, and may induce kidney toxicity if ingested.

A developing unborn child is particularly at risk from exposure to mercury. Exposure can adversely affect a child's developing brain and nervous system.

Employer duties

Under the Occupational Health and Safety Act 2004 (OHS Act), all employers must, so far as is reasonably practicable, provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors. Where the risk cannot be eliminated, it must be reduced so far as is reasonably practicable.

Employers must provide employees with the necessary information, instruction, training or supervision to enable them to do their work in a way that is safe and without risks to health. Employers must also ensure, so far as is reasonably practicable, that persons other than employees are not exposed to health and safety risks arising from the conduct of the employer's undertaking.

Where mercury containing products used in the workplace are classified as hazardous substances, such as mercury itself or mercuric chloride and mercuric acetate that are used in the synthesis of other compounds, additional employer duties apply under Part 4.1 (Hazardous Substances) of the Occupational Health and Safety Regulations 2017 (OHS Regulations). These duties include, but are not limited to:

• Eliminating or reducing any risks associated with the the hazardous substance at the workplace so far as reasonably practicable, using the hierarchy of controls.
• Providing and maintaining a hazardous substances register and obtaining current Safety Data Sheets (SDS) that are readily accessible to any employees who may be exposed to the hazardous substance.
• Ensuring containers in which hazardous substances are contained are labelled with the manufacturer or supplier's label.
• Ensuring a hazardous substance contained in any manufacturing plant process equipment (e.g. piping system, vessel, reactor etc.) which contained hazardous substances are identified to employees who may be exposed to the substance.
• Conducting atmospheric monitoring if there is uncertainty as to whether the exposure standard is or may be exceeded or where it is necessary to determine whether there is a risk to health.
• Providing health monitoring to employees exposed to mercury (inorganic) and who are reasonably likely to have an adverse effect to their health under the particular conditions at the workplace. Mercury (inorganic) is listed in Schedule 9 (Hazardous substances – requirements for health monitoring) of the OHS Regulations.

In addition to the employer duties under the OHS Act and OHS Regulations, employers should also prepare a scenario-specific emergency response plan (ERP) for loss of containment of mercury or mercury compounds, provide training to employees and make the ERP available to employees and emergency services (e.g. Fire Rescue Victoria).

Manufacturer / Supplier duties

Under the OHS Act, a manufacturer of products that contain mercury or mercury compounds must ensure, so far is reasonably practicable, that the product is manufactured to be safe and without risk to health if it is used for the purpose for which it is manufactured. The manufacturer must also:

• Ensure that the product has been tested / examined to perform its function in a safe manner and without risk to health.
• Provide adequate information to each person to whom the manufacturer provides the product to, this includes the purpose for which the product is manufactured, the results of any testing / examination and any conditions necessary to ensure the product is safe and without risk to health if used for the intended purpose.

A person who supplies a product that contains mercury or mercury compounds that is to be used at a workplace must ensure, so far as is reasonably practicable, that it is safe and without risk to health if it is used for the purpose for which it was designed, manufactured or supplied.

The supplier must also ensure that adequate information is provided to each person to whom the supplier is supplying the product to, this includes the purpose for which the product was designed and the conditions necessary to ensure the product is safe and without risk to health if used for the intended purpose.

In addition to duties under the OHS Act, manufacturers and importing suppliers of hazardous substances must comply with duties under Part 4.1 (Hazardous Substances) of the OHS Regulations.  These duties include but are not limited to:

• determining whether a substance contains hazardous substances before it is first supplied to a workplace
• preparing and providing a current SDS before the hazardous substance is first supplied to a workplace
• correctly labelling any container containing the hazardous substance in accordance with regulatory requirements

Dangerous goods laws apply

Mercury, mercury related compounds and mercury waste are classified as dangerous goods under the Dangerous Goods Act 1985 and Dangerous Goods (Storage and Handling) Regulations 2022 (DG laws).

Manufacturers, first suppliers and occupiers have duties under the DG laws to control risks related to mercury exposure and ensure the safe storage and handling of mercury in the workplace. These duties apply in addition to the duties under the OHS Act and OHS Regulations, described above.